ISG15 and systemic lupus erythematosus: The mRNA levels of OASL (median: 138.20, IQR 46.05–289.42 vs. 224.20, IQR 99.27–369.82, p = 0.047), OAS1 (median: 144.65, IQR 82.97–234.20 vs. 262.00, IQR 120.37–778.12, p = 0.013), ISG15 (median: 0.14, IQR 0.07–0.26 vs. 0.31, IQR 0.12–0.51, p = 0.044) and LY6E (median: 147.05, IQR 65.05–235.92 vs. 317.60, IQR 161.35–385.37, p = 0.030) in SLE patients that were anti-DNA (−) were significantly lower than those in patients with anti-DNA (+).